Wrapping machine



C. F. PRINCE WRAPPING MACHINE Aug. 6, 1957 6 Sheets-Sheet 1 Filed April16, 1954 INVENTOR C1. nee/vet EFF/w:

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ATTORNEYS United States Patent C WRAPPING MACHINE Clarence F. Prince,Springfield, Mass., assignor to Package Machinery Company, EastLongmcatlow, Mass, a corporation of Massachusetts Application April 16,1954, Serial No. 423,640

6 Claims. (Cl. 53--373) This invention relates to machines for wrappingrelatively thin fiat articles such as bacon or other food productspositioned on cardboard pallets.

Products of this kind are desirably wrapped in transparent wrappingmaterial such as acetate or other suitable sheet plastic material, thewrapper being sealed to preserve the product during display,refrigeration and storage.

It is the principal object of the present invention to provide a machinewhich will wrap and seal such articles at a relatively high speed and atthe same time draw the wrapper smoothly over the article so that thepackage presents a neat appearance with the contents clearly visiblethrough the transparent wrapper and to seal the article without inducingwrinkles or other distortions in the wrapper which would detract fromthe appearance of the package.

Other and further objects and advantages residing in the details ofconstruction and operation will be made apparent in the disclosure ofthe accompanying drawings and in the following specification and claims.

In the accompanying drawings,

Fig. 1 is a side elevational view of a machine embodying the invention;

.Fig. 2 is a view on a larger scale of the left hand end of the machineas viewed in Fig. 1;

Fig. 3 is a plan view of the structure shown in Fig. 2, the upperconveyor being removed; 7

Fig. 4 is a sectional detail view substantially on line 4-4 of Fig. 3;

Fig. 5 is a generally perspective view of the article locking means onthe transfer device;

Fig. 6 is a fragmentary side elevational view, similar to Fig. l but ona larger scale and showing certain of the operating mechanisms;

Fig. 7 is a sectional view substantially on line 77 of Fig. 8;

Fig. 8 is a sectional view substantially on line 8-8 of Fig. 6;

Fig. 9 is a sectional view substantially on line 9-9 of Fig. 8;

Fig. 10 is a view similar to Fig. 6 but with parts in section to showthe under-seam sealer and the associated mechanisms;

Fig. 11 is a sectional view substantially on line 11-11 .of Fig. 8;

Fig. 12 is a fragmentary view of the left hand portion of Fig. 11showing the parts in an intermediate position;

Fig. 13 is a sectional view, on a larger scale; substantially on line13-13 of Fig. 12;

Fig. 14 is a fragmentary plan view of the partially wrapped article; and

Fig. 15 is a bottom view of the wrapped and sealed article.

Referring to Figs. 1, 2, 3 and 4 the articles A including a cardboardpallet P are fed into the machine by a suitable conveyor 1 having pusherflights 2 which discharge the articles against the free end of a wrapperweb w and onto spaced supporting plates} of a, swinging,transferdevice4.

2,801,508 Patented Aug. 6,

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As the article and wrapper are moved onto the supporting plates 3 thewrapper is drawn around the forward edge of the article with the endportion a (Fig. 2) underlying the article. The transfer device is swungupwardly, as shown in Figs. 2 and 4, into alignment with an inclinedfolding channel 5. As the article is swung upwardly by the transferdevice the wrapper is laid over the top of the article by the aid of adraping roll 6 and flexible blanket member 7 and the partial articleencircling portion of the wrapper subsequently severed by a knife 8 toleave an end portion b sulficient to overlap the portion a and completethe encirclement of the article. The wrapper feeding, cutting anddraping means is that shown and described in the copending applicationof Lyon et al., Serial No. 58,592, filed November 5, 1948, and furtherdescription is therefor deemed unnecessary.

As the article and end portion of the wrapper are advanced onto plates 3by a flight 2 of the conveyor the central portion of the forward edge ofthe article and intervening wrapper are engaged, Figs. 3, 4 and 5, bymeans of a slide indicated at 9 and mounted for extension over theintermediate plate 3. Slide 9 is slidable on the transfer member 4 inguide members 10 and is forced back to the position of Figs. 3, 4 and 5when the article is fully on plates 3. Frictional resistance is providedfor the slide by a tension plate 11. As best shown in Fig. 5 the slidecarries a cross bar 12 having channeled pusher jaw receiving footmembers 13, which extend into the spaces between plates 3 and beneaththe article, and an upper member 14 having an. inclined forward edge 15between which and members 13 the forward edge of the package is heldclamped on the transfer member with the central portion of the palletedge and adjacent wrapper portions held in place. The cross bar 12 andmember 14 are mounted in fixed relation to the slide 9 by a bracket 16.

When forced back to the position of Figs. 3, 4, and5 with the leadingedge of the article, card, and wrapper clamped centrally, the wrapper onthe upper surface 9f the article adjacent the ends thereof is heldpressed under tension by a pair of spaced individually spring loadedpressure fingers 20 hearing on the article. Each finger 20 is adjustablyfixed on a bearing block 21 which is pivoted on an arm 22 journaledbetween collars on an elevator support shaft 23. The arms are held fromrotation by a bar 17 extending from the transfer device 4 through eacharm 22. The bearing blocks 21 extend to the other side of the pivotstherefor. Each is normally held ,under tension to depress its finger 20by a spring 24 (Figs. 2,3 and 4) connected to a hanger bracket 25fixedoneach arm 22. 1

Finger positioner members 26 are fixed. to the fingers 20 in dependingrelation thereto adjacent the pivotand serve to raise the fingers abovethe plates 3 at the lower receiving station in line with conveyor 1 bycontact against the stop abutments 27 (see Figs. 1 and 3). Thus thefingers are raised over plates 3 to receive the article thereunder. Asthe platform rises, the fingers press the underlying wrapper against thearticle and prevent the paper from slipping. The abutments 27 are fixedto the lower ends of frame arms 29 which also carry upper stop abutments30 against which the outer rear ends of the fingers 20 strike in theupper transfer position of the device (Fig; 2). The stops 30 serve toelevate the fingers 20 above the wrapper at the transfer station.

As the transfer device elevates the plates 3 into alignment with thewrapping and sealing channel 5 (Fig. 2) a depending pair of a series ofpairs of pusher members 31, carried by intermittently operated chains32, picks upthe article from the clamping slide. Two pairs ofjawsindicated generally at 33 (Figs. 2 and 11) pass between the edges ofthe plates 3 (see Fig. 3) with the lower jaws thereof extending,underneath the article throughwthe 14 (Figs. 3 and 5). The pushermembers thus advance the clamping slide 9 for movement forwardly of theplates 3. The recessed portions 34 permit jaws 33 to hold the packageand wrapper immediately on engaging member ,14 so as to grip the wrapperand article before the trans- .fer devicel4- lowers slide 9 and itsassociated parts out of the path of pushers 31 as the package isadvanced by the pushers. When the article advances onto the floor of thechannel (see Fig. 2) the portion b of the wrapper passes underneath thecard the wrapper being cut as previously mentioned to overlap theportion a and en- .circ le the article. 1 The wrapper encircled articlepasses iunder a pair of spaced hold down bars 35 while the trans- ,fermechanism with supporting plates 3 is lowered carrying the bracket 16 ofthe clamping slide clear of the pusher 31.

In the Wrapping channel the article is carried to two stations indicatedin Fig. l by arrows I and H at which stations heat sealing operationsare performed.

A wrapper encircled article at the first station in the wrapping channelis shown by Fig. 2. The first operation is to crimp the end tabs or thetubular portions of the wrapper extending beyond each end of the articleby pleating the extreme end portions thereof. As shown by Figs. 11, 12,and 13 a shoe 36 first clamps the outer ends of the tubular portions andthen a second shoe 37 draws the paper tightly across the article andheat seals the tubular extensions together intermediate the article andcrimped edge.

The pleats are formed so as to pull the ends of the extended portionsinwardly of the corner of the article, as indicated at c in Fig. 14, andto eliminate looseness of the wrapper at the corners. 'The shoe 36 alsotends to draw the intermediate portions of the wrapper between it andthe article into more or less taut condition whereupon the shoe 37forces the portions together for the heat sealing operation against aheater 79. The second shoe 37 to Y draw and seal the tubular portions isshown in operative position by Fig. 11. A snug and tightly fitting wrapis thus insured.

At the first station the long under seam at the underside of the packageis also heat sealed by a transverse sealer plate 38 (Figs. 2 and whichswings upwardly through an opening in the channel floor and against theoverlapping 'edges a and b of the wrapper during the dwell at said firststation.

' From the first heater station the partially sealed package isadVancedto a second heater station shown at the other end of the channel byFigs. 1, 6, and 8. Between these stations the sealed extensions arefolded under the ends of the package bythe tucking blades 39 anddiagonal tucker slots 40 (seeFigs. 8 and 9).

At the second heater-station as shown by Fig. 7 the tubular portions,now folded under the ends of the package, are heat sealed after whichthe package is discharged onto a delivery belt 41.

, During the entire passage through the channel to the second heaterstation the upper end portions of the package are held flatly in thechannel first by hold down bars 35 (Figs. 2, l0, and. 11) at the firststation and then by similar bars 42 dur'ing passage to the second heaterstation (Figs. 9 and 10). The hold down bars 35 and 42 are eachsuspended in operative position by parallel linkage from 'a support bar44 (Fig. 10) on each side of the channel, the

support 44 being vertically adjustable as on the slotted brackets 45anchored on channel frame mount 46. The parallel links 47 are loosely(as shown by Fig. 9 and Fig.

.11) mounted at each end on pivot pins so that the play in suchconnection will permit the bars 35 and 4-2 to conform V to the surfaceof the package and tilt as required during the passage of the articleunderneath the same. The hold down bars are adapted to-engage thewrapper surface to p of the frame mount 46 (Fig. 6).

maintain the wrapper in fiat relation on the contents, and in the caseof bars 35, tend also to assist in squeezing air out of the package.

At the second heater station three individually spring loaded fingers orpads 43 (Figs. 7 and 8) are pressed downwardly adjacent each end of thepackage to conform to any irregularities in package shape and thusinsure a tight underfold seal at each end. The pads 43 press the packageagainst heaters 80 for a secure heat sealing of the underfolded endtabs.

The end tab crimping members for the tubular portions at the firstheater station (Figs. 11 and 12), the pressure pads or fingers 43 at thesecond heater station (Fig. 7) and the heat sealer mechanisms at eachstation are mounted on shafts 5i} and 51 (Fig. 6) hung at each side ofthe channel by frame brackets 52 fixed to the frame mount 46. Thestationary portions of each mechanism are keyed to the stationary shaftwhile the movable portions are keyed to the movable shaft 51. v

The end tab crimping and pressing shoes 36 and 37 are carried by springloaded stems 53 and 54 of a rocker 55 keyed to shaft 51. The stems aremounted in pairs (see Fig. 8) on each rocker with stems 54 located atthe ends of the rocker and stems 53 positioned inwardly thereof. Asindicated by Fig. 12 the stems 53 extend vertically below the stems 54and accordingly the (shoe 36 strikes the crimping plate in advance ofthe shoe 37 striking the intermediate heat sealer plate. The crimper orpleater bottom plate 56 as best shown by Fig. 13 is provided with spacedrecesses 57 into Which the Wrapper tabs are pressed by the pleating ribs58 of the shoe 36.

Pressure pads 43 at the second heater station are also rocked bymovement of the shaft 51. As shown by Figs. 6 and 8 the pads are ingroups of three in number at each side of the wrapping channel and arecarried on lever arms 60 journaled on shaft 51. The outer ends 61 of thearms 60 are connected by tensioning springs 62 fixed thereto and attheir other ends to an overhead bracket mount 63 The springs thus urgethe pads 42 to the operative full line position of Fig. 7. Clamped onthe shaft 51 between spaced levers 60 are two release arms 65 (Fig. 6)at the inner sides of the outer arms 60. Arms 65 and collars 66 (Fig. 6)fixed on shaft 51 hold the arms 60 in position thereon. Release arms 65extend upwardly and outwardly of the shaft 51 and carry a release bar6'7 between their outer ends to engage an adjustable pin 68 threaded inan upstanding lug 69 on each lever arm 60. As shown by Fig. 7 theinoperative upper dotted line position of the pad 43 is obtained by theshaft 51 and arm 65 rotating in a counterclockwise direction wherein thebar 67 engages the pin 68 to force the arm 60 counterclockwise againstthe tension of spring 62. When shaft 51 is rocked in a clockwisedirection the bar 67 rotates to the full line position, the spring thenbeing free to swing arm 60 and press pad 43 on the top of the wrappedarticle. At the end of a sealing step the bar 67 rocks the arms 60counterclockwise to release the wrapped article.

Shafts 51 on each side of the channel are rocked intermittently, and insequence with the intermittent step by step travel of the chains 32carrying the pusher members 31, by a rocker shaft 70 driven by asuitable cam mechanism (not shown). Shaft 70 is linked to each shaft 51by arms 71 and 72 to a cranking collar 73 keyed to each shaft (see Figs.6 and 8).

As shown by Fig. 10, shaft 70 also operates through a collar 75 keyed toit and links 76 and 77 to pivot the heat sealer 38 on a pivot at 78. Theseat sealing mech anism as indicated by the numeral 73' for the crimpingand intermediate sealers at the first heater station (see Fig. 12), andas indicated by the numeral 89 for the flap undersealers at the secondheater station (see Fig. 7), are both mountedon the stationary shaft 59.V 7 When the undersealers at 86 have sealed the end flaps and thepressure pads 43 are released, the conveyor chain is advanced todischarge the article from the wrapping channel onto the delivery belt41 of Fig. 1. 1

What is claimed is:

1. In a machine for wrapping fiat articles having means to encircle thearticle with a wrapper sheet with portions of the wrapper overlappedbeneath the article, the Wrapper being wider than the article to formtubular portions extending outwardly of the ends of the article, awrapping and sealing channel, and means to intermittently advance theso-partially wrapped article through the channel with said tubularportions extending transversely of the channel; the combination ofclamping means positioned at the sides of the channel at a position ofrest of the article to clamp the outer end portions of each tubularextension against transverse movement, and heated clamping meansoperable, While the ends of the tubular extensions are held by saidfirst clamping means, to engage the portions of the tubular extensionsintermediate the clamped end portions and the adjacent end of thearticle to draw the wrapper tightly over the article and to seal thewrapper in so-tightened position.

2. The combination of claim 1 including means positioned in overlyingrelation to said channel between said clamping means to seal saidoverlapped portions of the wrapper beneath the article.

3. The combination of claim 1 in which an operating arm at each side ofsaid channel carries said first and second named clamping means, eachsaid arm being pivotally movable to swing the clamping means in anarcuate path against an adjacent tubular wrapper extension with saidsecond named clamping means being positioned on the arm outwardly ofsaid first named clamping means.

4. In a machine of the class described having means to encircle a fiatarticle with a wrapper sheet with portions of the wrapper overlappedbeneath the article and forming tubular portions extending outwardly ofthe ends of the article; in combination, a wrapping and sealing channel,

means to intermittently advance a partially wrapped article with saidtubular portions extending transversely of the channel, said channelhaving two positions of rest and at the first of said positions having:clamping means to hold the outer end portions of each tubular extensionagainst transverse movement and heated clamping means operable, whilesaid tubular extensions are held by the first clamping means, to clampthe portions intermediate said end portions and the adjacent end of thearticle to draw the wrapper tightly over the article and seal thewrapper in so tightened condition, and sealing means at said firstposition of rest in underlying relation to said channel between saidclamping means to seal overlapped portions of a wrapper beneath saidarticle, and means positioned between said positions of rest to foldsaid sealed extending portions around the ends of the article andagainst the underface thereof with means at said second position of restto seal said so-lfolded extensions to the wrapper portions covering theunderside of the article.

5. The combination of claim 4 in which said lastmentioned sealing meansincludes heated members engaging the underfolded tubular portions of thewrapper, and yielding means engaging the upper surface of the edgeportions of the article to press said portions against the heatedmembers.

6. The combination of claim 5 in which said yielding means comprises aplurality of spaced independently spring loaded fingers.

References Cited in the file of this patent UNITED STATES PATENTS1,953,096 Becker Apr. 3, 1934 1,953,097 Becker Apr. 3, 1934 2,350,132Rohdin May 30, 1944 2,604,744 Klimas July 29, 1952

